I would say that the color does not make any difference. I have placed white lights low and used them as fogs. My 2007 chevy 3/4 ton has factory fogs and they are white. They work better for illuminating the ditches to show me the deer/cattle/feral hogs that are hiding waiting to jump out in front of me than they do for fog driving. But they do help.
How often are you going to be driving in the fog? I have a pair on my truck, and they are keeping the original yellows that are still in them and functioning. Its a nostalgia thing with me. Someday, I may need new ones, and yellow blubs may not be available.
